code: def init_fn(worker_id):
      assert torch.get_num_threads() == 2
  
file_path: pytorch_geometric/test/loader/test_mixin.py
imports: import subprocess
  from time import sleep
  import pytest
  import torch
  from torch_geometric.data import Data
  from torch_geometric.loader import NeighborLoader
  from torch_geometric.testing import onlyLinux, onlyNeighborSampler
label_desc: Use image node_id 2 for calling a global function with example usage: init_fn(worker_id) without return types